


Can't Bury the Beast

by FamineArcher



Category: Katekyou Hitman Reborn!, 文豪ストレイドッグス | Bungou Stray Dogs
Genre: Arcobaleno Atsushi, Gen, Skull is Atsushi
Language: English
Status: In-Progress
Published: 2020-12-31
Updated: 2021-01-22
Packaged: 2021-03-10 19:34:19
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 3,919
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28442490
Author URL: https://archiveofourown.org/users/FamineArcher/pseuds/FamineArcher
Summary: Nakajima Atsushi is undercover when he gets scouted for the Strongest Seven. He goes.
Comments: 16
Kudos: 136





	1. Chapter 1

Nakajima Atsushi was undercover. He was investigating a lead about human trafficking in a circus as a stuntman named Skull DeMort. Then he was invited to a gathering of the “Strongest Seven.”

He went, and was introduced to the world of the Mafia before the others arrived.

Luce explained it all and warned him that the others would likely look down on him for being a civilian. “We both know you’re not, but that’s your secret to keep.”

As others began to arrive, “Skull” sat at the end of the long table quietly. Once everyone was there, Luce clapped her hands. “Let’s introduce ourselves, shall we? I’m Luce, the Sky of our group.”

“Reborn. I’m the world’s greatest hitman and the Sun.”

“Fon. I’m the Storm and a martial artist.”

“Lal Mirch of COMSUBIN. I’m the Rain.”

“Viper. Mist. Anything else will cost you.”

“I’m Verde, I’m a scientist, and I’m a Lightning.”

Atsushi felt all eyes on him. “I go by Skull, I’m the world’s best stuntman and apparently a Cloud.”

Reborn raised an eyebrow. “A stuntman? A civilian?”

“I’m not Mafia, if that’s what you mean.”

Lal snorted. “There must have been slim pickings if they chose a stuntman.”

He decided to be more honest. “Technically I’m a detective. I was undercover investigating a human trafficking operation. I should probably get back to that.”

“Evidence has already been sent to your agency regarding that case.” Luce told him. “Consider it a down payment.”

“Ah. Appreciated.”

“Alright, let’s have you lot move in.” The Sky chirped. “Rooms have already been prepared for each of you.”

The six others were led to a hallway with a group of doors. Each was labeled with a name.

Atsushi entered the door labeled “Skull” and began combing the room for bugs. He found seventeen plus three in the bathroom for a total of twenty.

The weretiger headed next door to the door labeled “Reborn.” He knocked and the door opened for him. “What do you want,  _ investigatore _ ?”

“How many bugs did you find?”

“Eighteen.” The man admitted.

“I found twenty. Did you check inside the mattress?”

“Damn.”

Fon joined them. “Twenty-one. One’s in the toilet’s tank.”

The other two swore. 

Atsushi was curious. “Is this normal for the Mafia? Because Yakuza don’t do this nearly as often.”

“It’s like saying hello.”

After the three of them had compared notes and removed all the bugs, all seven met in the lounge area that evening. “I have our first job.” Luce informed them. “There’s a small Family called the Acerbi running an organ smuggling ring. They take organs from unwilling donors and sell them all across the black market. They were the ones buying people in Skull’s human trafficking case.”

Atsushi growled quietly. Only Fon heard the noise. Luce continued. “Our job is to wipe them all out. Leave as few survivors as is possible. Here’s the floor plan.”

“Wipe them out?”

Reborn smirked. “Cold feet,  _ investigatore _ ?” He glanced at Atsushi.

“If you’re wondering if I’m gonna freeze up, the answer is no. This won’t be the first time I’ve killed someone. But to clarify, you want them all dead.”

“Yes.” Luce replied. “Illegal human organ harvesting is the lowest of the low. Lal and Viper, you’re on the ones that try to escape. Verde, I want surveillance disabled, no record of us being there. Reborn, the outbuilding. Fon and Skull, the main house and the basement. Burn anything you find that seems like research.”

Atsushi raised a hand. “Are there weapons available for use?”

The Sky led the six to a massive armory. As the others armed themselves, Atsushi picked up a small automatic weapon. The same kind Higuchi had shot at him with the first time they met. He took a second one and slung them across his shoulders, then grabbed a pair of gloves with clawlike blades attached to the fingertips, a replacement for his own claws.

The seven piled into a minivan and headed out. Luce drove.

Atsushi flexed his fingers absently. He would have to kill again. These ones, however, he’d feel no guilt over. He knew what organ trafficking did to the victims, having helped Kunikida on a case a while back.

The car stopped. “We’re here.”

Lal and Viper crouched at the perimeter, watching the house carefully. Reborn headed to the outbuilding. Fon and Atsushi approached the main house cautiously. The lights in the house went out. Verde was doing his job.

Atsushi inhaled deeply, memorizing Fon’s scent so even in the dark he would be able to track the older man. His tiger eyes would see in the dark, but just to be safe.

The pair opened the front door and walked in.

A flashlight almost blinded them. “Who the hell are you?”

Fon rolled his shoulders as more men piled into the room, surrounding the duo. “We’re the Strongest Seven.” he said nonchalantly, then lashed out to crush a man’s windpipe.

Atsushi drew his guns and started firing at the enemies. As the pair ripped through the house, he discarded the guns for metal claws, killing or maiming any who got in his way.

The two left the house full of corpses and on fire. Scattered corpses on the lawn proved that the perimeter had held strong. Reborn joined them as they walked. “How’d the  _ investigatore  _ do, Fon?”

“He held his own.” The martial artist replied.

“Hey, I’m a private detective. I have firearms training.”

For the first six months, he managed to hide the fact that so far from Fukuzawa, he had a monthly tiger transformation, but as always happened, he wasn’t lucky.

He was to meet Reborn at an empty building to keep watch on some important Mafia meeting, on the night of the full moon. He was hoping the meeting would end before the moon rose, but the moon rose before Reborn even got there. His helmet and jacket, which he had taken off to get comfortable, were destroyed by the tiger’s rampage.

Reborn was startled when he saw a white tiger standing over the remains of Skull’s clothes, and he immediately assumed the tiger had killed the detective. He shot.

The bullet bounced off the tiger’s fur, and the beast turned to fix a baleful eye on the hitman. It lunged.

As Reborn dodged and returned fire, he called Fon, their animal expert. “ _ Reborn? What happened at the meeting? _ ”

“Fuck the meeting, the  _ investigatore  _ is dead.”

“ _ How?” _

The hitman started to set up a trap, thankful the warehouse used to belong to a zoo. “A fucking bulletproof fucking tiger ate him and is trying to eat me!”

“ _ I’ll be right there. _ ” Fon hung up.

Reborn tripped the trap, catching the animal in a cage. He locked a thick manacle around the tiger’s neck, chaining it to the bars.

The tiger went still. It then hurled itself at the bars, trying to break free.

When Fon arrived, it was tired out and laying on the ground. The martial artist examined it. “A white Siberian Tiger. Rare. You say this ate Skull?”

Reborn showed the other the tattered clothes.

“The tiger’s got no blood on it, though. Not a drop. More likely-” Fon froze, looking the tiger in the eye. “Reborn, I think this  _ is _ Skull. See the ring of purple around its pupils?”

“ _ Porco dio! _ What could have done this?”

“Right, the Italian Mafia doesn’t care about the Gifted.” Fon remembered. “Have you ever heard of Ability-users?”

“Vaguely. You're saying someone’s Gift did this to Skull?”

“I’m saying he’s Gifted. Likely doesn’t even know it, from the looks of things.”

Reborn furrowed his brow. “So he turns into a violent beast and doesn’t know it. Sure.”

“Who struck first, Reborn? You, or it?”

The Sun looked down. “I thought it killed Skull. And I didn’t actually break the skin, it’s bulletproof.”

“Still leaves bruises.” Fon circled the cage. “So it was trying to defend itself. That makes more sense than a rampage. Call the others. This is important.”

When Atsushi woke up, he was in a cage with a shackle around his neck, just like the orphanage. He pressed himself into a corner and started hyperventilating.

“Yo, Skull.” He turned at Reborn’s voice. “Remember what happened last night?”

“The meeting-we were supposed to watch a meeting but...what happened?” He played dumb.

Fon turned his phone around to show Atsushi a picture of the tiger. “This is you last night.”

Lal and Viper were watching him warily, while Verde eyed him like a lab rat. “Very funny. Let me out of the cage, please?” His voice broke.

Reborn shook his head. “Not until we’re sure you aren’t going to turn and attack us.”

“Did I attack someone?”

Fon held up a hand to keep Reborn from talking. “Reborn provoked the tiger. It was defending itself. You don’t seem too surprised.”

“I always…” He thought of how much to tell them. “I lose time once a month. At night. I wake up and everything’s destroyed. Suppose that’s why.” He let out a harsh bark of laughter, remembering the orphanage, how they locked him up just like this. “At my orphanage, I guess they knew, because they’d lock me up before I lost time. I thought they just hated me, but now…”

“You are an Ability-user. Do you know about them?”

“My agency works with them closely. I know a lot.”

“When do you lose time?”

He pretended to think. “The night of the full moon. I think.”

Lal laughed. “Like a werewolf.”

“A were-tiger would be more appropriate.” Viper added dryly.

“Can I PLEASE be let out of the cage now?” Atsushi begged.


	2. Chapter 2

Atsushi had a dilemma. He was avoiding Reborn because the man wanted to train him in his Ability, which was uncontrollable this far from the president. The only way Atsushi knew to activate it other than the moon was to get badly injured, and he did not want to do that at all.

He had no idea what he was going to do to get Reborn off his back.

Fon knocked on his door. “Skull?”

Atsushi ran a hand through his dyed hair, two-toned eyes rolling. “If it’s from Reborn, he can stuff it!” He called.

“Actually, that’s what I wanted to talk to you about.”

“Fine, come in.” He opened the door.

“Have you always lost time on full moons?” Fon settled in the chair at Atsushi’s desk, while the weretiger sat on the bed. “Or is it only after a certain time in your life?”

“Always.” The detective answered truthfully. Until Fukuzawa, he’d always lost hours at night on the full moon, but never connected it to anything.

“So you’ve always had your Ability. I wonder why you never noticed it until now?”

“The orphanage I used to live in hid it from me, I think.” Atsushi thought for a moment. “I think that’s why I was treated poorly. They were scared of me.”

Fon nodded. “I see. And your coworkers in your detective group?”

“I only went on a rampage after Reborn attacked, right?”

“Yes.”

“So I would normally be calm enough to not do anything. I’ve come to and it had destroyed stuff, but not attacked anyone. Plus I lived alone.”

“Makes sense. Is there anything else you can think of that could be a part of your Ability?”

“I mean, maybe. I heal fast, but that could be the Cloud Flames.” Atsushi deflected.

Fon shrugged. “Either or. Regardless, you know Reborn just wants to help.”

“I’d rather not be the cause of his death, thanks all the same.”

“If we chained you up first-”

“NO!” He said instantly. “No chains! No cage!”

“Alright.” Fon raised his hands calmingly. “No cage. What about a locked room you can’t escape?”

“Only if it’s strong enough to keep people safe from me.”

“Verde has a lab room with blast doors and an observation window.” Fon offered. “Would that work?”

“Only if the window is reinforced.”

“Verde uses Lightning Flames on it whenever he does an experiment, so he’ll have to be there.”

“That should work.” Atsushi conceded. “I guess I’ll go find Reborn.”

He located the man with his tiger senses. Reborn smelled like a lizard covered in gunpowder and blood, so easy to locate.

“Reborn-senpai!” He called.

“Ah,  _ investigatore _ . I’ve been looking for you.”

“I know.”

“Tell me what you know about your Ability.”

He pretended to think. “I’m a tiger on full moons, I have good senses, and I heal fast which might actually be Cloud Flames. That’s all I know of.”

“Hm. I can work with this. If we dropped you into an enemy base on a full moon, that might solve the problem.”

“If I don’t get killed. I might be bulletproof, but I’m not sure I’m bomb-proof.” Atsushi felt compelled to point out.

“Maybe we can teach you to control the tiger.” Fon said from behind him. He’d heard the man approach and didn’t jump.

“How?”

“The Triads teach Flame control and temper control to their Flame Actives. Temper control is what we need right now. We need you to be in tune with yourself, to meditate.”

“Meditation?” Reborn hummed. “That might work. At least, it couldn’t hurt.”

And so Atsushi learned to meditate. It helped him gain a little control over the tiger, being able to give it general direction and keep it from hurting people he didn’t want hurt. He was able to change at will now, as well.

He sent a letter to Ranpo that just said

_ Found new job. Working with Italians. Took care of the tabby cat. _

He trusted Ranpo to deduce the rest and tell the others about it.

Luce had just told the Agency that he was needed for a job to help out an Italian group, but he knew Ranpo knew everything about what was actually going on.

He grew to like being in the group, the sense of camaraderie that formed after a few months.

Unfortunately, it wasn’t to last.


	3. Chapter 3

Luce, having given birth, led the Strongest Seven up a mountain. “We’re almost there.”

“You gonna tell us what’s going on once we get there?” Reborn drawled.

“I will.”

The guild that wafted off of her was a scent Atsushi did not like. He hung back to speak to Fon. “Whatever’s going on, she’s guilty about it.”

“Maybe this is bad, you mean.”

“Yeah.” The weretiger bit his lip nervously as they arrived at a clearing.

The Man in the Iron Mask, who had recruited him, was standing there. He’d called himself Checkerface when they met last.

“Now will you explain what’s-” Reborn was cut off by a light slamming into his chest. He began to glow.

One by one, the others were similarly impacted. Lal was shielded by a blond man, but both began to glow instead of just him.

When the glow cleared, Atsushi saw piles of clothes around him. He was still the same as ever, but felt much weaker.

“I see, your Ability kept your form the same. No matter, you will serve just as well.” Checkerface said, then vanished.

A naked baby Reborn emerged from his suit. “What is going on?!”

“We are Arcobaleno.” Luce said. “One third of the Tri-Ni-Sette. The Pacifiers take our Flame and convert it into energy to keep the world stable.”

Atsushi felt around his neck. There was a round pacifier hanging from it.

The others emerged from their piles of clothing, Viper clothed in Mist illusions.

“And why is Skull not tiny?!” Lal demanded.

“His Ability kept his form from changing, but make no mistake, he was not left unscathed.”

Atsushi sat down to be closer to eye level with the others. “It feels like I’m carrying weight on every part of my body. I’m weaker, too.” He sighed. “I’m not gonna be able to-wait a minute.” He thought for a second. “No, that wouldn’t work. The Vindice would have my head.”

“This complicates matters.” Fon frowned. “Nobody will take us seriously as babies.”

“I might have an idea about that, at least.” Atsushi offered. “We keep taking jobs once we’ve adjusted to this situation, make a name for ourselves even like this.”

“We’re gonna need an adjustment period.” Verde was staring at his hands. “My Flames feel weaker.”

Luce looked on, face drawn. “I do apologize for this, but it was necessary to keep the world in balance.”

Viper looked at her. “Did you have a choice in this?”

“Not any real choice, no.”

“Then you suffer no blame.”

Atsushi glanced over to Lal, who had a twisted scar on her cheek, and the blond man who’d shielded her. “I believe introductions are in order.”

“I’m Colonello, one of the commander’s trainees.”

“Let me guess. Protecting your superior officer is something hammered into you.” Reborn said.

“In this case, yes.”

Atsushi stood, feeling as though his weight was ten times heavier than usual. “We should return to the mansion. It’s not safe out here.”

He led the seven babies back to the mansion, then sat on the floor as they settled on the couch.

“We need clothes.” Verde pointed out.

“I can go into town and get some. You all look the same size.”

“But you’re rather eye-catching.” Fon said.

The weretiger smirked. “I can wash out the hair dye and dye it black instead. I also have black contacts I can use.”

“You dye your hair?”

He shrugged. “It was necessary for the Skull persona at the circus to be realistic.”

He went to wash out his dye and re-dye his whitish hair black. He put in contacts and wiped off his fake tattoo, removed his piercings, and didn’t put on any makeup.

When he walked back into the common area, the others almost didn’t recognize him.

Luce blinked. “That is much less obtrusive.”

Atsushi nodded. “I’ll be right back.”

He walked into town, bought a ton of baby clothes, and walked back to the mansion.

“I’m back! I even found a tiny suit for Reborn!”

Reborn snatched it and vanished into his room to put it on.

The others had to make do with t-shirts and pants in various colors.

Atsushi staggered to his room and fell face-first into his bed, taking out the contacts as an afterthought. The weight on his body was exhausting.

**Notes for the Chapter:**

> So Atsushi keeps his form, but not without consequences.  
> I'd love to hear your opinions on this chapter.


	4. Chapter 4

It took weeks of training, but they did manage to adjust.

Atsushi was the first to feel ready. “Any jobs I can take alone?”

Luce looked up from where she was feeding her daughter with a bottle. “Someone’s put a price on Francis Fitzgerald. Would you take that?”

“I’m not suicidal. The man’s Gifted, Luce. And he almost destroyed a city once. Something within the realm of possibility.”

She gave him another file and sent him on his way. He did jobs for a few months, building up the Arcobaleno’s reputation.

“Luce, what have you got today?

“Well, there is a hit out on a corrupt official in Padua.”

“Details?”

“A minor official who got on the wrong side of a Famiglia that has money to burn.” She handed him a folder from the pile near her.

He perused the file and nodded. “Did they request anything specific?” He had been desensitized to killing after his time with the others. Now it was just something he’d rather not do.

“They want it public.” She grimaced.

He grimaced as well. “Great. Anything else?”

“Let the witnesses see the pacifier. It’ll send a message.”

Atsushi nodded. “I’m off, then.”

He took a short airplane flight to Padua, a nice little city near Venice. He arrived at night and checked the information he was given.

The target liked to take walks along the river at night. Atsushi staked out the target’s home for a few days and planned.

One night, he followed the target to a party. He slipped in over the wall, wearing his helmet, and drew a pistol.

He took aim and fired three shots into the target’s chest. “That’s from the Bovino family.” He called.

The party-goers stared for a minute, then panicked.

Atsushi slipped away in the chaos and ran. He got on a plane before the police could find him, and was safe in the mansion before long.

“I’m back!”

Luce was knitting something while sitting in a baby-sized chair. “You were successful, I assume.”

“Killed the man at a party in full view of the party-goers. Where’s everyone else?”

“On their own jobs. Viper’s gathering information, Fon and Reborn are on hits, Lal and Colonello are reporting to the CEDEF, and Verde’s on an invention contract.”

He smirked. “Things are doing alright, then. Would it be ok if I returned to my Agency?”

“As long as you don’t give the Vindice cause to go after you.”

The weretiger shivered. He’d met the Vindice once and didn’t care to repeat the experience. “I’ll do my best.”

He got back onto a plane and went to Yokohama, with no dye in his hair or piercings on his face. He wore a collared shirt and nice slacks, with the pacifier tucked under his collar.

The young man had been away from the Agency for two years at that point, and was unsure if he’d still be welcome. He hesitated at the door.

It opened and Kyouka, a little taller, almost ran into him. “Oh, I’m sorry.”

“No, I was the one standing in the way.” He waved his hands.

She went on her way and he almost cried. Of course she didn’t recognize him. It had been two years, after all, and things were bound to change.

She turned. “Wait...Atsushi?”

He nodded. “I’m back.”

She ran to hug him.

He hugged her back.

She dragged him into the Agency and cleared her throat. All attention was focused on her and she pointed at him.

“Atsushi-kun!” Kunikida said in surprise.

“Hi…” He waved sheepishly. “Sorry about the wait.”

Ranpo raised an eyebrow. “I see. I’ll fill the others in later.” He remarked.

Atsushi spent the day catching up with the Agency.

He managed to hide the pacifier from them for a while, almost two years, but as with all secrets, it had to come to an end.

He was working on paperwork when Dazai dumped a bottle of water on his head as a practical joke.

The water soaked Atsushi’s head and his shirt clung to his body, revealing the pacifier around his neck.

“Ne, Atsushi-kun, what’s that?” Dazai queried.

Kunikida snapped to attention, as did everyone else.

He pulled the purple pacifier out from his clothes and let it dangle free. “It’s a long story, Dazai-san.”

“Is that a child’s teething toy?” Kunikida asked.

“It’s supposed to resemble one, yes.” Atsushi looked around, paranoid the Vindice would appear any moment. “I’m  _ really  _ not allowed to discuss it.”

Ranpo swallowed his mouthful of chips. “It’s true. This secret isn’t the safe kind.”

“I saw that thing on a tape from a murder case.” Tanizaki realized. “Atsushi-kun, what did you do while you were gone?”

“Again, I’m not at liberty to say.” The weretiger shifted nervously. “No matter how secret you try to keep it, They  _ will _ find out. I can’t risk that.”

Ranpo nodded along. “He’s telling the truth. Me knowing because of my deduction skills is one thing, but him or I telling you is another. It’s far too dangerous for you to know.”

With Ranpo’s backing, the others subsided, though they were still curious.

Atsushi stopped hiding the pacifier around them after that.

**Notes for the Chapter:**

> I enjoy all your feedback! Hope this is a good one!

**Author's Note:**

> Should I continue this? Or does it suck?


End file.
